Adsorptive Desulfurization of Propylmercaptan and Dimethyl Sulfide by CuBr2 Modified Bentonite

Adsorptive desulfurization for removing propylmercaptan （PM） and dimethyl sulfide （DMS） over CuBr2 modi- fied bentonite was investigated under ambient conditions in this work. A saturated sulfur capacity as high as 196 mg of S per gram of adsorbent was demonstrated. The influence of loading amount of Cu （II） and calcination temperature on adsorptive desulfurization was investigated. Test results revealed that the optimum loading amount of Cu （II） was 15%, and the calcination temperature was 150 ℃. The pyridine-FTIR spectroscopy showed that a certain amount of Lewis acid could contribute to the increase of adsorption capacity. Spectral shifts of the v（C-S） and v（Cu-S） vibrations were detected from the Raman spectra of the Cu （II） complex which was a reaction product of CuBr2 with DMS. According to the hybrid orbital theory and the complex adsorption reaction, the desulfurization of PM and DMS over the CuBr2 modified bentonite is ascribed to the formation of S-M （σ） bonds.